Improvement in boiler-coverings



R. THOMAS. Boiler Covering.

No. 197,000. Patented Nov. 13,1877.

IFF/E ITLEIY UNITED STATES PATENT OFFICE.

Bonner THOMAS, or BOSTON, it'ssssonnsnrrs.

IMPROVEMENT IN 'BOILERV-GOVERINGS.

Specification forming part of Letters Patent No. 197,000, dated November13, 1877 application filed H June 19, 1517.

inexpensive non-conductor; but when placed directly in contact with hotsurfaces it is he ble to become charred and tendered useless.

Asbestos is commonly used as a non-conducting covering, andit has beenused with hair, by first mixing asbestus fiber with silicate of soda,and placing it, while in a plastic condition, upon the surface to becovered, and

then the hair has been applied upon the'asp81 It will be observed thatbyusing cement as l the uniting means between the hair felt and bestus.3

The (fleet of this invention is to provide a combin hair and asbestoscovering which may 'be'readily applied to the surface to be coveredwithout separately mixing and manipulating the asbestos.

the usual hair felt, and

To do this I take a coat or cover it with silicate of soda or itsequivalent, mixed, if desired, with glue and flour, or either, and thenI apply to the hair felt so coated a covering of asbestos pulp or paper,made substantially in accordance with the plan practiced under thepatent toPeters,

The asbestus paper adheres to the hair, and, so incorporated with andforming a perreadily Figure 1 represents apiece of this improvedcovering in perspective.

The hair felt is designated by the letter a, and'the asbestos paper bythe letter b. The hair felt, on the surface next the pulp or paper b, iscoated with silicate of soda, provided manent face. for the hair, it maybe applied as a covering.

or not with glue and flour, or all combined,

which forms an adhesive cement, and causes the paper to adhere to thehair and form an' integral portion of the covering. The paper a face bwill'be placed in' contact with the surface to be covered."

This asbestus paper might be caused to adhere to the surface of otherusual fibrous sheets, to prevent such sheets from being injured ordestroyed ,byflre, or heat; but that is not herein claimed, because itis reserved for a separate application.

I have described silicate of soda as the principal ingredient of thecementitiousmatter, as it is considered superior to other substances;but I do not desire to limit my invention to its use, as any usual orsuitable, cement may i be employed-to cause the hair and asbestus iertoadhere together.

asbestos paper, the latter is left unbroken or unperforated withholesfor the passage of.

heat or line.

I. do not broadly claim the employmentof hair and asbestus, asl am awarethat they have been combinedin'difl'erent ways. I claim p Thecombination, with an independent-layer or sheet of hair felt, of anindependent layer or sheet of asbestos paper cemented thereto,

to form a portable covering fabric, having one face of hair felt and theother of asbestos paper, all substantially asfand'for the purpose

